The present invention relates to an electronically controlled diesel engine for a vehicle which may act as an air compressor in addition to acting as a power source for the vehicle. When acting in the air compressor function, one end cylinder is converted to the function to provide compressed air to air tanks on the vehicle. The air from this combination compressor and power cylinder may be used to fill air tanks which provide air for braking in vehicles such as heavy trucks. Various types of diesel engines may be modified to become an electronic engine-air compressor system in accordance with this invention.
Prior Art
Heretofore, diesel engines have existed which may be temporarily act as air compressors. One type of prior art diesel engine which could act as an air compressor involved tapping off pressurized air output from the turbo charger from the intake manifold. This prior art diesel engine is shown in U.S. Pat. No. 4,429,532. Diesel engines have a sets of combustion cylinders which have pistons which cycle in the cylinders when the engines are operated. Should fuel be shut off to the fuel injectors of one of these combustion cylinders during engine operation while maintaining the piston movement, efficient compression of air entering the cylinder will occur and exhausting to the exhaust manifold. The prior art diesel engine shown in U.S. Pat. No. 4,429,532 did not take advantage of this air compression in the cylinder to pressurize air for the vehicle air system.
Diesel engine cylinders have an intake valve and an exhaust valve. The intake valves, exhaust valves and injection valves cycle open and closed to allow the pistons to reciprocally move in the cylinders through an intake stroke, a compression stroke, an expansion stroke, and an exhaust stroke. Another prior art diesel engine electronically varied the movement of two or half of the pistons in the cylinders of an in-line four cylinder diesel engine to reverse motor the impacted cylinders. The fuel injectors in the reverse motoring cylinders would be shut off and the compressed gas would be discharged via the intake valves to the intake manifold. An example of this type prior art engine is shown in U.S. Pat. No. 5,226,401. Although this engine did involve air compression in an engine cylinder starved of fuel, there was a complex scheme involved in varying the movement of the intake and exhaust valves from their normal cycling for combustion. Additionally, the engine shown in U.S. Pat. No. 5,226,401 was not engaged to the vehicle's air system to allow controlled delivery of pressurized air. Air compressed in this prior art engine was redirected to the intake manifold to assist in engine pollutant reduction.
Another type prior art engine with a compressor function is shown in U.S. Pat. No. 3,744,934 where some of the cylinders may be converted to a compressor function. An engine internal switching means was required to accomplish the dual function so as to vary intake and exhaust valve cycling.
None of the prior art mentioned diesel engines with air compressor functions could be easily manufactured from simple modifications to an existing diesel engine exhaust system without varying intake and exhaust valve cycling.
Heretofore, an electronically controlled diesel engine for a vehicle which may act as an air compressor has not been suggested which utilizes the exhaust stroke of one piston of a cylinder of the engine, is capable of discharging the exhausted air to the vehicle air system, does not vary the cycling of the engine intake and exhaust valves and which may be easily manufactured with simple modifications to an existing diesel engine.